1. Field of the Invention.
The present invention relates to a street sweeper having a vertical chain driven conveyor apparatus. The vertical chain driven conveyor apparatus may be provided with an automatic chain adjustment system. The vertical chain driven conveyor apparatus also may be provided with a locking adjustment mechanism to prevent the chains losing tension when the sweeper is turned off. The sweeper may also be provided with an initialization program to restore tension in the chains upon startup and prevent sweeping operations until a desired chain tension has been indicated.
2. Description of Related Art.
Street sweepers are a common necessity to maintaining the safety and beauty of streets and highways throughout the world. Street sweepers come in a variety of shapes and sizes for a variety of different functions. Some surfaces must be maintained meticulously clean for safety purposes, such as airport runways, taxiways, and helicopter landing strips. Other surfaces require cleaning to prevent flooding, such as sweeping the leaves from highways and streets to prevent ditches, culverts and storm drains from becoming clogged and preventing the runoff of snow melt and storm water.
In small towns and suburban neighborhoods, small, quiet, dust-less, and pollution free street sweepers are demanded. In order to make a smaller street sweeper, a vertical chain driven conveyor apparatus may be applied to reduce the overall length of the street sweeper. Vertical chain driven conveyors suffer a drawback that horizontal chain conveyors are not as hampered by. When the chains stretch and become loose in a horizontal chain driven conveyor, the middle portion of the chain merely sags, but the chain does not become dislodged from the sprockets holding the chain at either end of the conveyor.
However, in a vertical chain driven conveyor system, tension must be maintained in the chains at all times, otherwise the chain will fall off the bottom sprocket leading to perhaps catastrophic damage to the conveyor system. Additionally, if the chains are not held in tension, the operation of the conveyor will be impeded or ultimately fail.
As the chains of the conveyor elongate due to wear, the tension force decreases without adjustment. To maintain proper adjustment, the chains must be routinely readjusted. Chain adjustment is laborious, time consuming, and to the unskilled, dangerous. Not only will a street sweeper operator need to check the chain tension before beginning sweeping operations, it may be necessary to adjust the chain tension at least a few millimeters every few hours, depending upon the rigors of the sweeping operation.
It can be seen that there is a need for a street sweeper having a vertical chain driven conveyor apparatus that automatically adjusts the chain tension and prevents damage to the street sweeper and saves the operator time. The present invention fulfills these and other needs, and addresses other deficiencies of prior art implementations.